Q: Heater does not blow hot air.

Hi there. Check the coolant level in the radiator and make sure that its full. Check the heater core valve near the firewall in the engine compartment and see if valve is working. Feel the heater hoses before the valve and after the valve and see if the hoses have a different temperature. If the temperature is different, then the heater control valve is not working. If the temperature is the same, then there could be a blend door that is sticking open to the outside air. Look for any vacuum hoses that would be disconnected to make the blend doors not work. If your blend doors are electric, then check the wiring to the blend doors and make sure that they are not shorting to the ground. If you need further assistance with your heater not working, then seek out a professional, such as one from Your Mechanic, to help you.